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Showing papers by "Robert Fagard published in 1986"


Journal ArticleDOI
TL;DR: Little or no benefit from treatment could be demonstrated in patients over the age of 80 years, the great majority of whom were women, and there was some evidence that treatment effect decreases with advancing age.

203 citations


Journal ArticleDOI
TL;DR: In this urban Bantu population of Kinshasa, Zaïre, age and body weight are the major predictors of systolic pressure in youths and the major Predictors of both syStolic and diastolic Pressure in adults.
Abstract: The 24-hour urinary excretion of sodium, potassium, calcium, and magnesium and their relationship to arterial blood pressure were investigated from December 1983 to May 1984 in a 10% random sample (n = 666) of urban Bantu of Kinshasa, Zaire. In youths aged 10-19 years, blood pressure averaged 109/60 mmHg, and the 24-hour urinary excretion of sodium, potassium, calcium, and magnesium averaged 84 mmol, 30 mmol, 483 mumol, and 2 mmol, respectively. After adjustment for age and body weight, a weak positive association became apparent between diastolic pressure and the urinary sodium to potassium ratio in girls and all youths. In adults aged greater than or equal to 20 years, blood pressure averaged 124/72 mmHg, and the 24-hour urinary excretion of sodium, potassium, calcium, and magnesium averaged 87 mmol, 33 mmol, 828 mumol, and 1.88 mmol, respectively. After adjustment for sex, age, body weight, and pulse rate in all adults, systolic pressure was significantly and positively correlated with urinary sodium excretion and negatively correlated with urinary potassium excretion, while diastolic pressure was weakly associated with urinary calcium excretion. In women, an independent and significant association was also observed between systolic pressure and 24-hour urinary sodium. When instead of the 24-hour urinary excretion of sodium and potassium, the sodium to potassium ratio was considered as an independent variable in multiple regression analysis, both systolic and diastolic pressure were independently and positively related to the sodium to potassium ratio in all adults. These results indicate that in this urban Bantu population, age and body weight are the major predictors of systolic pressure in youths and the major predictors of both systolic and diastolic pressure in adults. The sodium to potassium ratio did contribute to the prediction of blood pressure in girls and when, in youths as well as in adults, both sexes were considered together. Urinary calcium was associated with diastolic pressure only in all adults.

39 citations


Journal ArticleDOI
TL;DR: Evidence is provided that the adrenoceptors mediating the release of renin at rest and during exercise in humans are partially of the beta 1-subtype, whereas beta 2-adrenergic receptors probably play only a minor role in the control of ren in secretion, especially at exercise.
Abstract: The relative role of beta 1- and beta 2-adrenoceptors in the regulation of blood pressure and plasma renin at rest and during exercise was studied in 17 normal male volunteers. They performed, in a randomized order and according to a double-blind crossover study design, three graded and uninterrupted exercise tests until exhaustion after being pretreated during 3 consecutive days with a placebo, with a predominantly beta 1-blocker (atenolol, 50 mg once/day), or with a predominantly beta 2-blocker (ICI 118551, 20 mg 3 times/day). Both drugs caused a decrease of heart rate, but the reduction by ICI 118551 was less pronounced at rest and no additional decline occurred at exercise. ICI 118551 did not affect blood pressure at rest, but during exercise diastolic blood pressure was higher than after a placebo. Atenolol lowered systolic blood pressure at rest and suppressed the exercise-induced increase in systolic blood pressure. At rest and during exercise plasma renin activity was lowered by predominantly beta 1-blockade and unchanged during beta 2-antagonism. The exercise-induced increase in plasma renin was, however, not affected by the beta 1-blocker. After atenolol the urinary excretion of aldosterone was decreased but the plasma aldosterone concentration was not changed. ICI 118551 did not alter plasma or urinary aldosterone. Our results therefore provide further evidence that the adrenoceptors mediating the release of renin at rest and during exercise in humans are partially of the beta 1-subtype, whereas beta 2-adrenergic receptors probably play only a minor role in the control of renin secretion, especially at exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

24 citations


Journal ArticleDOI
TL;DR: In normal young subjects, global LV pump function is not affected by beta 1- or by beta 2-blockade, despite the negative chronotropic effect of both drugs.
Abstract: Pharmacological and radio-ligand binding studies have recently indicated the existence of beta 2-adrenoceptors in the human heart. Their physiological role, however, remains to be elucidated. The present study investigated in 17 normal, young volunteers the effect on resting left ventricular (LV) function of two types of beta-blockers; a predominant beta 1-adrenoceptor antagonist (atenolol, 50 mg once daily) and ICI 118,551 (20 mg t.i.d.), a new, predominant beta 2-antagonist. LV function was assessed using M-mode echocardiograms and systolic time intervals. Atenolol, ICI 118,551, and placebo were given according to a randomized, double-blind, cross-over protocol. As compared with placebo, both drugs caused a decrease in resting heart rate, but the reduction by ICI 118,551 was less pronounced. Systolic blood pressure was only reduced by atenolol 8 mm Hg on average. Cardiac output was decreased to the same extent following treatment with atenolol (-20%) as after ICI 118,551 (-17%). These decreases in cardiac output were related to the beta-blocker-induced bradycardia, since stroke volumes were not affected during either selective beta 1- or beta 2-blockade. In addition, all other echocardiographic variables reflecting LV pump function, such as fractional shortening, velocity of diameter change and of displacements, pre-ejection period, and the ratio of PEP/LVET, were not different from placebo. We conclude that in normal young subjects, global LV pump function is not affected by beta 1- or by beta 2-blockade, despite the negative chronotropic effect of both drugs.(ABSTRACT TRUNCATED AT 250 WORDS)

17 citations


Journal ArticleDOI
TL;DR: Nitrendipine appeared to be more efficient than acebutolol in reducing blood pressure and the N-induced fall in blood pressure was achieved after 2 weeks, and Pulse rate and plasma renin activity in the N group were slightly increased and body weight was decreased at the end of the active treatment period.
Abstract: The short-term efficacy of nitrendipine (N) as a first stage antihypertensive drug in black patients has been assessed and compared with acebutolol (A) in a double-blind study. Forty patients were randomized and after a 4 week run-in period on placebo, the active treatment was administered for 6 weeks starting with 20 mg N or 200 mg A once daily. The dose was increased up to 60 mg N or 600 mg A as needed. Nitrendipine appeared to be more efficient than acebutolol in reducing blood pressure and the N-induced fall in blood pressure was achieved after 2 weeks. After 2 and 6 weeks on N, the recumbent blood pressure was decreased by 13% and 12% for the systolic and by 14% and 11% for the diastolic pressure. The concurrent decreases in the A group averaged 4% and 5% for the systolic and 5% and 10% for the diastolic pressure after 2 and 6 weeks. Pulse rate and plasma renin activity in the N group were slightly increased and body weight was decreased at the end of the active treatment period.

17 citations


Journal ArticleDOI
TL;DR: Evidence is provided that beta 2-adrenergic receptors are involved in the regulation of the plasma levels of glucose and lactate during exercise, and that at moderate exercise the serum free fatty acids concentration was lower during beta 1-blockade than during placebo.
Abstract: The effect of beta 1- or beta 2-antagonism on the plasma levels of glucose, lactate, triglycerides, and free fatty acids was studied in seventeen normal male volunteers. All subjects performed three graded and uninterrupted exercise tests until exhaustion. Prior to each exercise test they received in a randomized order during three consecutive days either placebo or a predominant beta 1-blocker (atenolol, 50 mg once per day) or a predominant beta 2-blocker (ICI 118,551, 20 mg t.i.d.), according to a double-blind cross-over study design. Atenolol increased the plasma level of glucose at rest but did not influence the rise in plasma glucose during exercise. ICI 118,551 did not change the resting plasma glucose level, but it prevented the exercise-induced rise in plasma glucose, observed during placebo. During beta 1-antagonism the plasma lactate concentration at rest and during or after exercise was not different from placebo. During beta 2-blockade the exercise-induced rise in plasma lactate tended to be suppressed, and during recovery the plasma lactate levels were significantly lower than during placebo. The serum triglycerides concentration at rest and exercise was not altered, either by beta 1- or by beta 2-antagonism. Atenolol and ICI 118,551 did not affect the serum level of free fatty acids at rest, but at moderate exercise the serum free fatty acids concentration was lower during beta 1-blockade than during placebo. Our results provide further evidence that beta 2-adrenergic receptors are involved in the regulation of the plasma levels of glucose and lactate during exercise.

14 citations


Journal Article
TL;DR: The long-term effect of dietary sodium restriction and repletion suggests either the involvement of a mechanism which can only be slowly reversible or a mechanisms which is irreversible so that normalization takes place only when new red cells are released into the circulation.
Abstract: The erythrocyte concentration and fluxes of sodium and potassium were investigated in normal white male subjects during dietary sodium restriction and repletion, each period lasting for 16 weeks. During dietary sodium restriction the intra-erythrocyte sodium concentration decreased and the red cell ouabain-sensitive 86Rb-uptake increased; no significant changes were observed in the ouabain-insensitive fluxes of sodium such as the total, frusemide-resistant and frusemide-sensitive Na+-efflux and the Na+, Li+-countertransport. The decrease in the intra-erythrocyte sodium concentration could result from an increased Na+,K+-ATPase pump activity. The latter increase could be secondary to the early decrease in a digitalis-like plasma inhibitor and the late increase could be facilitated by the late rise in the intracellular ATP concentration, which is the energy supplier for this pump. During the subsequent first month of sodium repletion the intra-erythrocyte sodium concentration remained low, the red cell ouabain-sensitive 86Rb-uptake and ATP concentration remained elevated and returned to baseline only after 16 weeks. This long-term effect suggests either the involvement of a mechanism which can only be slowly reversible or a mechanism which is irreversible so that normalization takes place only when new red cells are released into the circulation.

7 citations


Journal Article
TL;DR: It can be concluded that parental hypertension in normotensive African blacks is associated with increased intraerythrocyte sodium concentration.
Abstract: Blood pressure and intraerythrocyte sodium and potassium concentration were investigated in 59 male inhabitants of an urban quarter of Kinshasa, aged 10 years and older. Two subjects were excluded because they were on antihypertensive treatment. Seventeen subjects were normotensive with both parents normotensive (group 1); 9 subjects were normotensive with at least one hypertensive parent (group 2); 5 subjects were untreated hypertensives (group 3) and 26 subjects could not be classified (group 4). Systolic pressure and intraerythrocyte sodium concentration (expressed in mmol/1 cells) were significantly higher in normotensive subjects with a positive family history of hypertension (group 2) than in normotensive males of comparable age, weight and height, born to normotensive parents (group 1). Untreated hypertensives (group 3) were older and their intraerythrocyte sodium concentration was higher in comparison to normotensives without positive family history of hypertension. The intraerythrocyte potassium concentration did not differ significantly among groups 1, 2 and 3. When the first three groups of participants, or all the subjects with the exclusion of treated hypertensives, were considered, no relationship could be demonstrated between the level of blood pressure and the intraerythrocyte sodium and potassium concentration. It can be concluded that parental hypertension in normotensive African blacks is associated with increased intraerythrocyte sodium concentration.

5 citations


Journal Article
TL;DR: Sodium concentrations in erythrocytes are lower in women during the luteal phase of the menstrual cycle than in women studied during the follicular phase and in men as mentioned in this paper.
Abstract: Sodium concentrations in erythrocytes are lower in women during the luteal phase of the menstrual cycle than in women studied during the follicular phase and in men. Sodium cotransport activity is lower in women during the follicular phase than in men. Women taking oral contraceptives show no monthly variations in erythrocyte sodium concentrations. Subjects with a family history of essential hypertension have higher sodium concentrations in erythrocytes than those with a different family background, partly because of reduction in sodium cotransport activity. Negroes have marked erythrocyte sodium accumulation due to lower activity of the sodium-potassium pump and cotransport system; they also have reduced sodium-lithium counter-transport. There is no difference between negroes with or without haemoglobin S. There are no changes in erythrocyte potassium concentrations in relation to sex, menstrual phase, race, familial essential hypertension, presence of haemoglobin S or use of oral contraceptives. These physiological variations indicate the factors which must be standardized to study sodium concentrations in cells and sodium transmembrane flux.

4 citations


Journal Article
TL;DR: Investigation of the relationships between blood pressure and 24-h urinary sodium, potassium, calcium and magnesium in adult men and women of urban Bantu of Zaire indicates that age, body weight, pulse rate, sex and the sodium: potassium ratio contribute to the prediction of systolic and diastsolic blood pressure, while urinary calcium was only associated with diastolic pressure.
Abstract: The relationships between blood pressure and 24-h urinary sodium, potassium, calcium and magnesium were investigated in adult men and women constituting a random sample of urban Bantu of Zaire. Blood pressure and the 24-h urinary sodium, potassium, calcium and magnesium averaged 124 +/- 20/72 +/- 14 mmHg, 87 +/- 51 mmol, 33 +/- 19 mmol, 828 +/- 91 mumol and 1.9 +/- 1.6 mmol, respectively. After adjusting for sex, age, body weight and pulse rate, systolic pressure was significantly and positively correlated with urinary sodium in all subjects and in women taken separately; it was also negatively correlated with urinary potassium, while diastolic pressure was weakly associated with urinary calcium. When instead of the 24-h urinary sodium and potassium the sodium: potassium ratio was considered as an independent variable in multiple regression analysis, it was correlated with both systolic and diastolic pressure. Our results indicate that age, body weight, pulse rate, sex and the sodium: potassium ratio contribute to the prediction of systolic and diastolic blood pressure, while urinary calcium was only associated with diastolic pressure.

3 citations



Journal ArticleDOI
TL;DR: Tibalosine reduced blood pressure at rest and during exercise independently of opioidergic mechanisms, and this hypotensive action may be accompanied by sodium and fluid retention.
Abstract: In a randomized double-blind protocol, 12 healthy male volunteers were studied twice at rest and during exercise after pretreatment for 1 week with placebo or 150 mg daily of the new alpha 1-adrenoceptor antagonist tibalosine. Six subjects received, on both experimental days, an intravenous infusion of saline and the other six received the opioid receptor antagonist naloxone. Combined measurements taken during rest and exercise showed tibalosine, on average, to decrease mean intraarterial pressure by 4.7 mm Hg and heart rate by 3.5 beats/min. Urinary volume and sodium excretion were transiently reduced by tibalosine as compared with placebo. Opioid antagonism by naloxone stimulated the pituitary-adrenal axis, but had no effect on the influence of tibalosine, as shown by hemodynamic, respiratory, and most humoral measurements. However, on interruption of exercise, opioid antagonism counteracted the inhibition of the plasma renin-angiotensin system by tibalosine, probably through the naloxone-induced increase in epinephrine release. In conclusion tibalosine reduced blood pressure at rest and during exercise independently of opioidergic mechanisms. This hypotensive action may be accompanied by sodium and fluid retention.


Book ChapterDOI
01 Jan 1986
TL;DR: Thirty-seven top-ranking athletes underwent 24-h Hoiter monitoring and pauses occurred in 19% and resulted from sinus arrest, with the longest pause lasted 2.5 sec.
Abstract: Thirty-seven top-ranking athletes underwent 24-h Hoiter monitoring. Pauses longer than 2 sec occurred in 19% and resulted from sinus arrest. The longest pause lasted 2.5 sec. Second-degree atrioventricular block was noted in 13%.